XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475)
Contourites are deposits formed by along-slope bottom currents and are therefore sensitive to changes in current velocity, sediments supply and paleoceanographic conditions. They are typically associated with high accumulation rates making these archives ideal for paleoenviromental reconstructions....
Main Authors: | , , , , , , , |
---|---|
Format: | Conference Object |
Language: | unknown |
Published: |
2017
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/44303/ https://hdl.handle.net/10013/epic.50651 |
id |
ftawi:oai:epic.awi.de:44303 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:44303 2023-05-15T18:01:02+02:00 XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) Jiménez-Espejo, Francisco Gruetzner, Jens Bahr, André Sierro, Francisco J. Ohkouchi, Naohiko Hall, Ian R. Hemming, Sidney R. LeVay, Leah J. 2017-03-22 https://epic.awi.de/id/eprint/44303/ https://hdl.handle.net/10013/epic.50651 unknown Jiménez-Espejo, F. , Gruetzner, J. orcid:0000-0001-5445-2393 , Bahr, A. , Sierro, F. J. , Ohkouchi, N. , Hall, I. R. , Hemming, S. R. and LeVay, L. J. , Expedition 361 Scientists (2017) XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) , XRF Core Scanning 2017, National Taiwan University, Taiwan, 20 March 2017 - 24 March 2017 . hdl:10013/epic.50651 EPIC3XRF Core Scanning 2017, National Taiwan University, Taiwan, 2017-03-20-2017-03-24 Conference notRev 2017 ftawi 2021-12-24T15:42:49Z Contourites are deposits formed by along-slope bottom currents and are therefore sensitive to changes in current velocity, sediments supply and paleoceanographic conditions. They are typically associated with high accumulation rates making these archives ideal for paleoenviromental reconstructions. Nevertheless, they are also occasionally affected by winnowing of fine particles and erosion/deposition of allochthonous material, which alters the grain-size and mineralogy. These processes can, as such, promote significant bias in proxy interpretation compared with other pelagic deposits. X-ray fluorescence (XRF) core-scanning is ideal to assess elemental variations in these high accumulation rate sequences. The comparison between lithological changes, Natural Gamma Ray and other parameters with XRF scanning data, along with statistical analysis can provide very useful information to support improved proxy interpretation. Using this approach at Site U1387, (detrital contourite system at Gulf of Cadiz), results indicate that the Zr/Al ratio represents a promising proxy for bottom current speed and show the transition from a hemipelagic to a contouritic system during the Miocene/Pliocene transition. Carbonate content and Ba/Al ratio appear to represent paleo-productivity variations and later to be completely overprinted by current activit y. At Site U1475 (carbonate contourite system at Agulhas Plateau) Zr content is just one artifact associated with high Sr content and the Ca/Sr ratio appears to be a more promising proxy for contourite reconstruction that is influenced by carbonate dissolution by deep corrosive waters. Comparing both locations we can conclude that proxies associated with the continuous background sediment settling over the seafloor (e.g. planktonic foraminifera) do not appear to be severely biased in countourite systems. Conference Object Planktonic foraminifera Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Contourites are deposits formed by along-slope bottom currents and are therefore sensitive to changes in current velocity, sediments supply and paleoceanographic conditions. They are typically associated with high accumulation rates making these archives ideal for paleoenviromental reconstructions. Nevertheless, they are also occasionally affected by winnowing of fine particles and erosion/deposition of allochthonous material, which alters the grain-size and mineralogy. These processes can, as such, promote significant bias in proxy interpretation compared with other pelagic deposits. X-ray fluorescence (XRF) core-scanning is ideal to assess elemental variations in these high accumulation rate sequences. The comparison between lithological changes, Natural Gamma Ray and other parameters with XRF scanning data, along with statistical analysis can provide very useful information to support improved proxy interpretation. Using this approach at Site U1387, (detrital contourite system at Gulf of Cadiz), results indicate that the Zr/Al ratio represents a promising proxy for bottom current speed and show the transition from a hemipelagic to a contouritic system during the Miocene/Pliocene transition. Carbonate content and Ba/Al ratio appear to represent paleo-productivity variations and later to be completely overprinted by current activit y. At Site U1475 (carbonate contourite system at Agulhas Plateau) Zr content is just one artifact associated with high Sr content and the Ca/Sr ratio appears to be a more promising proxy for contourite reconstruction that is influenced by carbonate dissolution by deep corrosive waters. Comparing both locations we can conclude that proxies associated with the continuous background sediment settling over the seafloor (e.g. planktonic foraminifera) do not appear to be severely biased in countourite systems. |
format |
Conference Object |
author |
Jiménez-Espejo, Francisco Gruetzner, Jens Bahr, André Sierro, Francisco J. Ohkouchi, Naohiko Hall, Ian R. Hemming, Sidney R. LeVay, Leah J. |
spellingShingle |
Jiménez-Espejo, Francisco Gruetzner, Jens Bahr, André Sierro, Francisco J. Ohkouchi, Naohiko Hall, Ian R. Hemming, Sidney R. LeVay, Leah J. XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
author_facet |
Jiménez-Espejo, Francisco Gruetzner, Jens Bahr, André Sierro, Francisco J. Ohkouchi, Naohiko Hall, Ian R. Hemming, Sidney R. LeVay, Leah J. |
author_sort |
Jiménez-Espejo, Francisco |
title |
XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
title_short |
XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
title_full |
XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
title_fullStr |
XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
title_full_unstemmed |
XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) |
title_sort |
xrf core-scanning signal interpretation in miocene carbonate and siliciclastic contourite deposits (iodp sites u1387 and u1475) |
publishDate |
2017 |
url |
https://epic.awi.de/id/eprint/44303/ https://hdl.handle.net/10013/epic.50651 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
EPIC3XRF Core Scanning 2017, National Taiwan University, Taiwan, 2017-03-20-2017-03-24 |
op_relation |
Jiménez-Espejo, F. , Gruetzner, J. orcid:0000-0001-5445-2393 , Bahr, A. , Sierro, F. J. , Ohkouchi, N. , Hall, I. R. , Hemming, S. R. and LeVay, L. J. , Expedition 361 Scientists (2017) XRF core-scanning signal interpretation in Miocene carbonate and siliciclastic contourite deposits (IODP sites U1387 and U1475) , XRF Core Scanning 2017, National Taiwan University, Taiwan, 20 March 2017 - 24 March 2017 . hdl:10013/epic.50651 |
_version_ |
1766170353378263040 |